1. Technical Field
The invention relates to apparatus and methods for constructing three-dimensional images.
2. Discussion of the Related Art
This section introduces aspects that may be helpful to facilitating a better understanding of the inventions. Accordingly, the statements of this section are to be read in this light. The statements of this section are not to be understood as admissions about what is in the prior art or what is not in the prior art.
One way to form a three-dimensional (3D) image involves using a hologram. In one form, a hologram is a permanent optical recording medium whose local transmissivity records relative amplitude and phase information from a wave front of a coherent light beam that has been scattered by the 3D scene being imaged. The permanent optical recording medium may be produced by developing a photographic medium that has been exposed to a light interference pattern. The light interference pattern is made, e.g., by interfering a coherent light beam scattered by the 3D scene with a coherent reference light beam.
To produce the 3D image, the hologram is re-illuminated with an appropriate coherent light beam. The re-illuminated hologram generates a first outgoing light beam that produces a 3D image of the scene used to make the hologram. The first outgoing light beam has a wave front on which the relative phases and relative amplitudes are substantially those of the light beam that was originally scattered by the scene during the production of the hologram. The illuminated hologram also generates a second outgoing light beam that produces a false 3D image of the scene that was used to make the hologram.